So I figured I'd bring up this issue even though it doesn't really affect us a whole lot, just figured I'd get some input.

We have two dogs, Eli(will be three in Jan 2014 and is fixed) and Cato(just turned 1,not yet fixed).
Cato is really interested in other dogs, though greets them with his hackles up. Never had any issues there though, he just seems cautious.

Eli however has always been extremely standoffish with other dogs, we always just attributed it to his breeds(German Shep/Akita). Even when we brought him home as a puppy, he would sniff them, but then not care to play with them. As he got older, it started turning aggressive to where he would sniff for a couple seconds and suddenly a fight would ensue.
On walks nine times out of ten if another dog attempts to approach him or they get too close, he'll snarl and try to lunge at them to keep them at bay.

He's walked on a prong collar which more or less eliminates his ability to lunge, and we use a bark collar as well and it's greatly improved this issue among others. Now usually he is fine to just sit and let the other dog pass as long as there is a good 6+ feet between them. There are 2-3 exceptions for dogs that have caused a lot of issues for him in the past, but most of them belong to seasonal cottagers so we only have to deal with them in the summer.(Aside from 1)

The weird thing is though, that there have been the very select few dogs he's been fine with. Our other dog(male) for one(whom we brought home as a puppy),our in-laws shepherd mix that he grew up with, our seasonal neighbors' two cocker spaniels(male and female), and just recently, a female mastiff puppy.
Again, he's fairly standoffish with them, doesn't really play much, just wants to sniff.The only dogs he actually plays with is our Cato and my in-laws dog whom he grew up with.

We like to play fetch in our unfenced yard as well as it's his favorite game. Due to the bark collar he is now able to ignore most dogs passing by and other distractions which has been a fantastic improvement. Just this past long weekend there is a st.Bernard who came onto our property and Eli chased him off just to the far side of our neighbor's driveway twice. No attempts to make direct confrontation, just seemed to want him off our property.

He also was playing with Cato the other night and Cato ran into my neighbor's yard to greet her dog(one of the ones that has caused a lot of issues for Eli) and Eli, probably thinking cato spotted a rabbit took off after him and my neighbor flipped out yelling for me to get Eli away from her.
I mean, I know he doesn't like her dog(or her for that matter, understandably) but he wouldn't run into some other dog's territory just to attack them or anything. Even before we started working on the aggression issues he wouldn't have, and as soon as he seemed to realize what was happening, he came right back with no attempts to engage her dog.

Now, my question is that is there some way to figure out what exactly causes this behavior in him? He was never attacked or anything by another dog to cause it, although when we got him, we lived in the boonies so as much as we tried to socialize him, it probably wasn't enough.

Any thoughts though?

He's absolutely fantastic otherwise. Huge cuddlebug and just an all around goofy suck. He's great and patient with our other dog. Great alert dog when someone unknown is on our property, smart,loyal,loves to play. Definitely a one-family kind of dog. I'm almost 40 weeks pregnant and he seems to be taking all the changes in stride as well. He seems to know he's allowed in the nursery, but that playing in there's not allowed. He nuzzles the baby items and my belly. I just could not ask for a better companion in every other way.

So I figured I'd bring up this issue even though it doesn't really affect us a whole lot, just figured I'd get some input.

We have two dogs, Eli(will be three in Jan 2014 and is fixed) and Cato(just turned 1,not yet fixed).
Cato is really interested in other dogs, though greets them with his hackles up. Never had any issues there though, he just seems cautious.

Eli however has always been extremely standoffish with other dogs, we always just attributed it to his breeds(German Shep/Akita). Even when we brought him home as a puppy, he would sniff them, but then not care to play with them. As he got older, it started turning aggressive to where he would sniff for a couple seconds and suddenly a fight would ensue.
On walks nine times out of ten if another dog attempts to approach him or they get too close, he'll snarl and try to lunge at them to keep them at bay.

He's walked on a prong collar which more or less eliminates his ability to lunge, and we use a bark collar as well and it's greatly improved this issue among others. Now usually he is fine to just sit and let the other dog pass as long as there is a good 6+ feet between them. There are 2-3 exceptions for dogs that have caused a lot of issues for him in the past, but most of them belong to seasonal cottagers so we only have to deal with them in the summer.(Aside from 1)

The weird thing is though, that there have been the very select few dogs he's been fine with. Our other dog(male) for one(whom we brought home as a puppy),our in-laws shepherd mix that he grew up with, our seasonal neighbors' two cocker spaniels(male and female), and just recently, a female mastiff puppy.
Again, he's fairly standoffish with them, doesn't really play much, just wants to sniff.The only dogs he actually plays with is our Cato and my in-laws dog whom he grew up with.

We like to play fetch in our unfenced yard as well as it's his favorite game. Due to the bark collar he is now able to ignore most dogs passing by and other distractions which has been a fantastic improvement. Just this past long weekend there is a st.Bernard who came onto our property and Eli chased him off just to the far side of our neighbor's driveway twice. No attempts to make direct confrontation, just seemed to want him off our property.

He also was playing with Cato the other night and Cato ran into my neighbor's yard to greet her dog(one of the ones that has caused a lot of issues for Eli) and Eli, probably thinking cato spotted a rabbit took off after him and my neighbor flipped out yelling for me to get Eli away from her.
I mean, I know he doesn't like her dog(or her for that matter, understandably) but he wouldn't run into some other dog's territory just to attack them or anything. Even before we started working on the aggression issues he wouldn't have, and as soon as he seemed to realize what was happening, he came right back with no attempts to engage her dog.

Now, my question is that is there some way to figure out what exactly causes this behavior in him? He was never attacked or anything by another dog to cause it, although when we got him, we lived in the boonies so as much as we tried to socialize him, it probably wasn't enough.

Any thoughts though?

He's absolutely fantastic otherwise. Huge cuddlebug and just an all around goofy suck. He's great and patient with our other dog. Great alert dog when someone unknown is on our property, smart,loyal,loves to play. Definitely a one-family kind of dog. I'm almost 40 weeks pregnant and he seems to be taking all the changes in stride as well. He seems to know he's allowed in the nursery, but that playing in there's not allowed. He nuzzles the baby items and my belly. I just could not ask for a better companion in every other way.

Yes , my thought is you should not be bringing your dogs to any parks knowing they'll get standoffish or try to lunge at other dogs they could end biting a child that is walking their dog . My dog was attacked by a dog that act just like your dogs do . And I was the one that end up having a to bring my dog to the vet on a Sunday . Now I am trying to get the owner of the dog that attacked my dog to buy my vets bills. And I would not put too much faith in a bark collar ,it will not keep a dog from running after another dog.

xcaer, like barkingdog, I too have some very strong thoughts on the matter. You are taking risks and I have to be really honest, if you were my neighbor and this has happened more than once on any level, I probably wouldn't be too happy. I am VERY happy to hear that your dog inflicted no physical damage to the other dog. But the owner and her dog were 'traumatized' to some degree without a doubt.

Imagine if another dog threatened or attacked your dog in your yard. Imagine if they wounded your dog. Try to imagine if it was a terrible wound, or worse. You would be furious, so would I and depending on the relationship you have with your neighbour...they may still be very upset. The reason doesn't matter because there is NEVER a good to be attacked on your own property. There is NO DEVICE that I know of that will keep your neighbour's safe from your dog 100% of the time. Anti bark collars do NOT work 100% of the time. The threat that happened to your neighbour's dog is likely still in your neighbour's mind. Your neighbour probably doesn't feel safe anymore, I know I wouldn't.

I don't know how big your property is, but If I were your neighbor I'd want your yard 100% fenced or your dogs on leash 100% of the time. Simple as that.

If after my dog was threatened/attacked, if I saw that these things were not done, I'd be very very upset and as much as I love all animals I'd probably call animal control. It is legally your responsibility to protect other people and property from harm from your dog. It's also part of being a good neighbor.

Please please try to rectify this situation to your NEIGHBOUR's satisfaction. The risk level to your neighbour's dog should be zero.

Although it's true that your neighbor could also put up a fence, and possibly split the costs - your dog was the attacker, and your dog may well attack again.

After your neighbors are protected, then group obedience training for your dogs is highly recommended. And I'd neuter the intact dog as well.

Hope that wasn't too harsh - just calling it like I hear it and trying to help you avoid potential future conflicts with neighbours and potentially police officers/animal control.

I know for a fact if the OP lived in New Hampshire and their dog attacked another dog that dog would had been shot on the spot with no questions asked. I am very concerned about child getting bitten in the face . My granddaughter was walking over to pet the dog that attacked my dog for no reason. My daughter was there too and we both where horrifies to think that her daughter and my grandchild could had gotten attacked too.
I hope my grandchild learned a very valuable lesson from this whole thing , I know I did. It only take a few seconds for a dog to run across yard and lunge at child playing with their dog in their own yard.